Orthopedic cements comprising a barium apatite contrast agent

Abstract

Methods are provided for producing settable compositions, e.g. pastes or clays, that set into calcium phosphate products and include a barium apatite contrast agent. In the subject methods, dry reactants and a setting fluid are combined with a barium apatite contrast agent, and the combined reactants are mixed to produce the settable composition. A feature of the invention is that the barium apatite contrast agent is particulate agent in which the particles have a size sufficient to provide a “peppered” appearance to the cement when imaged, such as when radiographically imaged. Also provided are the compositions themselves as well as kits for preparing the same. The subject methods and compositions produced thereby find use in a variety of applications, including hard tissue repair applications, such as vertebroplasty applications.

1 . A method of producing a composition that sets into a solid product, said method comprising: 
 combining:    (a) a setting fluid;    (b) dry reactants; and    (c) a contrast agent comprising a particulate barium apatite population having an average diameter ranging from about 200 to about 400μ;    in a ratio sufficient to produce said composition.    
     
     
         2 . The method according to  claim 1 , wherein said solid product is a calcium phosphate product.  
     
     
         3 . The method according to  claim 1 , wherein said dry reactants comprise a calcium source and a phosphate source.  
     
     
         4 . The method according to  claim 1 , wherein said setting fluid comprises said contrast agent.  
     
     
         5 . The method according to  claim 1 , wherein said dry reactants comprise said contrast agent.  
     
     
         6 . The method according to  claim 1 , wherein said contrast agent is present in said composition in an amount ranging from about 10% to about 35%.  
     
     
         7 . The method according to  claim 6 , wherein said composition is a paste.  
     
     
         8 . The method according to  claim 1 , wherein said setting fluid is a solution of a soluble silicate.  
     
     
         9 . The method according to  claim 2 , wherein said composition sets into said calcium phosphate containing product in a period of time ranging from about 5 to 10 minutes.  
     
     
         10 . The method according to  claim 2 , wherein said calcium phosphate containing product has a compressive strength ranging from about 25 to 100 MPa.  
     
     
         11 . A composition that sets into a calcium phosphate containing product, wherein said composition is produced by the method according to  claim 2 .  
     
     
         12 . The composition according to  claim 11 , wherein said contrast agent is present in said composition in an amount ranging from about 10% to about 35%.  
     
     
         13 . A method of repairing a hard tissue defect, said method comprising: 
 applying to the site of said defect a flowable composition that sets into a calcium phosphate containing product, wherein said composition is produced by the method according to  claim 1 .    
     
     
         14 . A kit for use in a preparing a flowable composition that sets in an in vivo fluid environment into a calcium phosphate product, said kit comprising: 
 (a) dry reactants comprising a calcium source and a phosphate source;    (b) a setting fluid or components for producing the same; and    (c) a contrast agent comprising a particulate barium apatite population having an average diameter ranging from about 200 to about 400μ.    
     
     
         15 . A packaged calcium phosphate cement, said packaged cement comprising: 
 a tubular element separated into a first compartment and at least one additional compartment by a removable barrier;    (i) dry reactants comprising a source of calcium and phosphate present in said first compartment;    (ii) a setting fluid or components thereof present in said at least one additional compartment; and    (iii) a contrast agent comprising a particulate barium apatite population having an average diameter ranging from about 200 to about 400μ present in either said first compartment, said at least one additional compartment or in a second additional compartment.    
     
     
         16 . The packaged calcium phosphate cement according to  claim 15 , wherein said removable barrier is a clip.  
     
     
         17 . The packaged calcium phosphate cement according to  claim 15 , wherein said removable barrier is a frangible barrier.  
     
     
         18 . The packaged calcium phosphate cement according to  claim 15 , wherein said setting fluid is a solution of a soluble silicate.